Vehicles may include computers programmed to recognize speech, and allow an operator to control, e.g., infotainment systems, navigation systems, emergency response systems, etc., via spoken commands. A voice recognition system may be optimized for widely used or standard pronunciations and may further be programmed to expect particular commands. In some examples, commands which are spoken with an accent, or do not conform to expected commands, may not be understood by the vehicle computer, leading to frustration for the vehicle operator or other occupant.